pulpinoexperiment

An experimental repository containing IP-XACT packaging of PULPino RISC-V microcontroller by pulp-project.org: https://github.com/pulp-platform/pulpino

Based on PULPino release in August 2017.

Setup

Update submodule pulpino:

git submodule init
git submodule update

Update all pulpino IPs, see README.md in pulpino for full instructions:

cd pulpino
./update-ips.py

Directories

• ip-xact: IP-XACT description files
• pulpino: Submodule directory for original PULPino implementation
• rtl: RTL implementation files for glue logic and wrappers

Notes on packaging

The following lists problems faced in the design in IP-XACT point of view:

• top.sv, peripherals.sv:
  • gpio_padcfg is 2-dimensional([6][32]) - Can't be used in bus definition
  • Left as ad-hoc port
• axi_node_intf_wrap.sv:
  • a vector of buses declared - Cant' be expressed in bus interfaces
  • Within the project the number of interfaces is always a constant
  • Created a new wrapper with bare ports and a set number of interfaces
• riscv-core.sv:
  • Parameter N_EXT_PERF_COUNTERS = 0 => signal ext_perf_counters_i boundaries are [-1:0] - IP-XACT port boundaries must be positive
  • Set default value to 1 which sets signal width to 1, not connected
• zero-riscy-core: zeroriscy_cs_registers
  • Parameter N_EXT_CNT = 0 => signal ext_counters_i boundaries are [-1:0]
  • Set default value to 1 which sets signal width to 1, not connected
• ifdefs
  • To be replaced with design configurations and isPresent attribute
• generate loops - IP-XACT cannot express n instances
  • Replaced with static number of instances
• hierarchical modules with additional logic, usually muxes -- Split stray(glue) logic into new components in directory rtl

New RTL components split from stray logic in hierarchical files:

• core_region_demux
• csr_logic
• csr_mux
• mux_mem
• spi_master_fsm
• uart_registers
• zero_riscy_registers